Allen J. Roussel

Clinical and pathologic features of cloned transgenic calves and fetuses (13 case studies)

The neonatal abnormalities, treatments and outcomes in a group of 13 cloned transgenic calves and fetuses that progressed into the third trimester of pregnancy are described. From these 13 fetuses, 8 calves were born live, 4 stillborn fetuses were recovered from 3 cows that died 7 d to 2 mo before term, and 1 aborted fetus was recovered at 8 mo gestation. All fetuses and calves were derived from the same male fetal Holstein fibroblast cell line transfected with a beta-galactosidase marker gene. Six calves were delivered by Cesarian section and two by vaginal delivery between 278 and 288 d of gestation. Birth weights ranged from 44 to 58.6 kg. Five of the 8 live born calves were judged to be normal within 4 h of birth based on clinical signs and blood gas measurements. One of these 5 calves died at 6 wk of age from a suspected dilated cardiomyopathy. Three of the 8 calves were diagnosed with neonatal respiratory distress immediately following birth, one of which died (at 4 d of age) as a result of pulmonary surfactant deficiency coupled with pulmonary hypertension and elevated systemic venous pressures. Similar findings of chronic pulmonary hypertension were also observed in 2 of 5 fetuses. Placental edema was present in both calves that later died and in the 2 fetuses with cardiopulmonary abnormalities. Hydrallantois occurred with or without placental edema in 6 cows, and only 1 calf from this group survived. The 6 cows without hydrallantois or placental edema produced 5 live calves and 1 aborted fetus. The cardiopulmonary abnormalities observed in the calves and fetuses occurred in utero in conjunction with placental abnormalities, and it is likely that the cloning technique and/or in vitro embryo culture conditions contributed to these abnormalities, although the mechanism remains to be determined.

Meal size and starch content affect gastric emptying in horses

REASONS FOR PERFORMING STUDY Feeding practices have been associated with colic in horses. If meal size and composition have an effect on gastric emptying, this could be one of the mechanisms by which feeding practices are related to the occurrence of colic. OBJECTIVES To evaluate the effect of meal size and starch content on solid phase gastric emptying. METHODS Solid phase gastric emptying of 3 different radiolabelled meals, small low-starch (SmLS), small high-starch (SmHS) and large high-starch (LgHS) meals, was measured in 5 horses by scintigraphy using 99mTc-disofenin. Data were compared among meals using nonlinear mixed-effects models and paired t tests. RESULTS On a percentage basis, SmHS emptied significantly faster than LgHS and SmLS emptied significantly faster than SmHS meals. However, when meals of unequal size were compared by emptying rate in g/min and Kcal/min, LgHS emptied significantly faster than SmHS. CONCLUSIONS Meal size and composition affect gastric emptying. POTENTIAL RELEVANCE Further work needs to be performed in order to substantiate the possibility of a relationship between digestive functions and occurrence of colic and gastric ulcers.

Fluid Therapy in Mature Cattle

Fluid therapy for mature cattle differs from that for calves because the common conditions that result in dehydration and the metabolic derangements that accompany these conditions are different. The veterinarian needs to know which problem exists, what to administer to correct the problem, in what quantity, by what route, and at what rate. Mature cattle more frequently suffer from alkalosis; therefore, acidifying solutions containing K(+) and Cl(-) in concentrations greater than that of plasma are frequently indicated. The rumen provides a large-capacity reservoir into which oral rehydration solutions may be administered, which can save time and money.

Use of Walpole's solution for treatment of goats with urolithiasis: 25 cases (2001–2006)

OBJECTIVE To determine results of ultrasound-guided cystocentesis and percutaneous infusion of Walpoles solution for treatment of male goats with urolithiasis. DESIGN Retrospective case series. ANIMALS 25 male goats with urolithiasis treated with Walpoles solution. PROCEDURES Information obtained from the medical records included signalment, degree of urethral obstruction (partial vs complete), pertinent examination findings, concurrent illnesses, diet, other treatments administered, duration of hospitalization, whether the obstruction resolved, and outcome (ie, discharged vs euthanized). RESULTS 14 (58%) animals had complete urethral obstruction, and 10 (42%) had partial obstruction (degree of urethral patency was not recorded in 1 animal). Walpoles solution was infused once in 18 (72%) animals, twice in 6 (24%) animals, and 3 times in 1 (4%) animal. The amount of Walpoles solution required to achieve the target urine pH of 4 to 5 ranged from 50 to 250 mL. In 20 (80%) goats, the urethral obstruction resolved, and the goat was discharged. The remaining 5 (20%) goats were euthanized because of unresolved urethral obstruction. Six of the 20 (30%) goats that were discharged were reexamined because of recurrence of urethral obstruction. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that ultrasound-guided cystocentesis in combination with percutaneous infusion of Walpoles solution may be a useful treatment in male goats with obstructive urolithiasis.

Effects of Shipping and Storage Conditions of Fecal Samples on Viability of Mycobacterium paratuberculosis

Johnes disease is characterized by chronic granulomatous enteritis of ruminants caused by Mycobacterium paratuberculosis infection. Early diagnosis of infected animals is necessary to reduce contamination of the environment and to control disease spread through feces (3, 6). About 75% of positive animals are either low or very low shedders (7, 8). Diagnostic samples for M. paratuberculosis identification are generally collected, shipped, and stored under various conditions that may influence the viability of M. paratuberculosis (2, 4, 5), thus changing the true status of the infected animal; in fact, the culture status especially of individual low or very low shedder animals could change from positive to negative. The aim of the present study was to mimic the most relevant conditions of shipment and storage of clinical samples obtained from naturally infected cattle and to study the effects of these conditions on the detection of M. paratuberculosis by standard bacteriological culture and real-time PCR. Fecal samples were collected from 11 cows confirmed to have Johnes disease; samples were transported on ice and stored as described in Table ​Table1.1. Fecal samples were tested for colony counts on Herrolds egg yolk agar slant (three tubes each for three dilutions with mycobactin J and one without mycobactin J) (9) and by immunomagnetic bead capture of M. paratuberculosis from feces and extraction of genomic DNA from captured M. paratuberculosis, followed by PCR (1). TABLE 1. Pairwise comparison of treatment group transport and storage conditions of clinical fecal specimens Several of the first- and second-dilution tubes had an M. tuberculosis organism too-numerous-to-count status; thus, data analyses were restricted to dilution 3. The mean colony counts at week 16 were compared across treatments, using analysis of variance (ANOVA) (SPSS version 13.0 software for Windows; SPSS Inc., Chicago, IL). Pairwise comparisons of treatment means between treatment groups were performed with the Tukey correction for multiple comparisons. Results for each tube were dichotomized into positive or negative, based on the presence of at least one colony. Fishers exact test (intercooled STATA version 9.2; STATA, College Station, TX) was used to compare the proportions for positive tubes and cattle. Significance was defined as a P value of <0.05 for all analyses. Pairwise comparisons (ANOVA) between treatment means identified a significantly higher number of colonies with treatment 5 than with treatment 3 (P = 0.04). Treatments 1, 2, 4, 5, and 6 had a significantly higher proportion of positive tubes than treatment 3. At the individual animal level, significantly larger proportions of cattle were classified as positive for treatments 1, 5, and 6 than for treatment 3. All of the real-time PCR results were positive for the presence of M. paratuberculosis under all of the conditions tested (treatments 1, 3, and 6). While samples from treatments 1 and 6 were found to be positive using both of the detection methods, only 5 of 11 tubes were positive for fecal culture for treatment 3, and all samples were found to be positive by using real-time PCR. Our study indicates that the storage of the samples at −20°C had adverse effects on the viability of M. paratuberculosis (5 of 11 samples were culture positive in treatment 3). Although all samples were positive by real-time PCR, the higher cycle threshold value in treatment 3 indicates the loss of viable bacteria and/or DNA quality. Treatment 3 may often be used by producers or veterinarians when they are sampling small populations or in individual suspected cases of Johnes disease. Thus, DNA-based PCR could be an alternative for situations where intermediate or long-term storage is necessary. Short-term storage of fecal samples at 4°C and longer term storage at −70°C appear to have no deleterious effects on M. paratuberculosis viability, but short-term storage at −20°C should be avoided as it substantially reduces the viability of the bacteria in the sample.

Are feeding practices associated with duodenitis-proximal jejunitis?

REASONS FOR PERFORMING STUDY Feeding concentrate has been putatively associated with risk of development of duodenitis-proximal jejunitis (DPJ); however, this association has not been evaluated systematically in a controlled study. OBJECTIVES To determine whether there was evidence that feeding practices were associated with increased odds of developing DPJ employing a case control study. HYPOTHESIS The amount of concentrate fed daily to horses is significantly greater among horses that develop DPJ than control horses with either lameness or other types of colic. METHODS Feeding practices of cases of DPJ diagnosed between 1997 and 2003 were compared with those of 2 populations of control horses (colic controls and lameness controls) admitted to the clinic from the same time period. Following multiple imputation of missing data, comparisons were made using polytomous logistic regression. RESULTS Horses with DPJ were fed significantly more concentrate and were significantly more likely to have grazed pasture than either control populations; DPJ horses were significantly more likely to be female than were lameness horses. Results were unchanged after adjusting for bodyweight of the horse. CONCLUSIONS Feeding and grazing practices differ among horses with DPJ relative to horses with other forms of colic and lame horses. POTENTIAL RELEVANCE The observed magnitudes of association were not sufficiently strong to merit diagnostic/predictive application; however, these observations, if substantiated by other studies, might provide important aetiological clues.

Control of paratuberculosis in beef cattle.

As with any susceptible livestock species, the key to control of paratuberculosis in beef cattle is to reduce exposure of the susceptible calves to Mycobacterium avium subsp. paratuberculosis (MAP)–contaminated feces. Because beef calves remain with mature, potentially shedding cattle until weaning, control strategies are aimed at providing an environment with the least possible fecal burden and removing MAP shedders as soon as possible. Testing and culling or separation may be more important in beef cattle than in dairy cattle. Seedstock owners have greater potential for economic loss from paratuberculosis, making control program more financially attractive to them than to commercial beef cattle producers.

Gastrointestinal Motility and Disease in Large Animals

An understanding of the relationship between gastrointestinal (GI) motility and disease is imperative for the proper treatment of large animal patients, especially as new therapeutic agents become available. However, the abundance of information that has become available in the last 2 decades makes gaining this understanding a formidable task. This article summarizes the changes in GI motility caused by some common diseases and conditions encountered in large animal practice, such as GI obstruction, postoperative ileus, resection and anastomosis, diarrhea, endotoxemia, GI parasitism, hypocalcemia, and pregnancy. J Vet Intern Med 1996;10:51–59. Copyright

Benefits of obtaining test-negative Level 4 classification for beef producers in the Voluntary Bovine Johne's Disease Control Program

The US Voluntary Bovine Johnes Disease Control Program (VBJDCP) stipulates the national standards for Johnes disease (JD) control, and herds classified as test-negative at Level 4 of the VBJDCP have the greatest likelihood of being non-infected. A questionnaire survey of owners of VBJDCP test-negative Level 4 beef herds was conducted to describe perceived benefits of attaining Level 4 status. Thirty-nine of the 40 producers returned completed or partially completed surveys. Sixty-four percent (23/36) of herds contained 50 or less test eligible cattle. Twenty-seven percent (10/37) of producers reported increased marketing opportunities as a goal for enrollment in the VBJDCP. Classification at test-negative Level 4 status in the VBJDCP led to increased marketing opportunities for more than one-third (13/35) of the producers. Twenty-five percent (9/36) of the producers reported significant and 39% (14/36) marginal benefits (financial and non-financial) as a result of participation in the VBJDCP. The median (range) reported annual benefit was

Comparison of calf weaning weight and associated economic variables between beef cows with and without serum antibodies against or isolation from feces of Mycobacterium avium subsp paratuberculosis

0 (